Goitre : A goitre or goiter , is a swelling of the neck or larynx resulting from enlargement of the thyroid gland (thyromegaly), associated with a thyroid gland that is functioning properly or not.
Goitre is treated according to the cause. If the thyroid gland is producing too much T3 and T4, radioactive iodine is given to the patient to shrink the gland. If goitre is caused by iodine deficiency, small doses of iodide in the form of Lugol's Iodine or KI solution are given. If the goitre is associated with an underactive thyroid, thyroid supplements are used as treatment. In extreme cases, a partial or complete thyroidectomy is required
Hypothyroidism : Hypothyroidism often called underactive thyroid, is a common endocrine disorder in which the thyroid gland does not produce enough thyroid hormone.
Treatment
Hormone replacement
Most people with hypothyroidism symptoms and confirmed thyroxine deficiency are treated with a synthetic long-acting form of thyroxine, known as levothyroxine
Liothyronine
Adding liothyronine (synthetic T3) to levothyroxine has been suggested as a measure to provide better symptom control
Desiccated animal thyroid
Desiccated thyroid extract is an animal-based thyroid gland extract. It is a combination therapy, containing forms of T4 and T3